Four-sided elastomer mount

ABSTRACT

A shock isolator for simultaneously isolating shocks and for supporting a static load in an axial offset compression mode comprising a four-sided elastomer having a first elongated support surface and a second elongated support surface with the laterally offset from each the elastomer rotated at a point between the first support surface and the second support surface to thereby simultaneously provide shock and vibration attenuation while providing axially offset support.

FIELD OF THE INVENTION

This invention relates to shock isolators and, more specifically, to ashock isolator that can simultaneously provide compressive supportwithout reliance on a direct axial compressive path through the isolatorand without significant bias in a single direction.

CROSS REFERENCE TO RELATED APPLICATIONS

None

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

None

REFERENCE TO A MICROFICHE APPENDIX

None

BACKGROUND OF T HE INVENTION

Various elastomeric materials have been used, or suggested for use, toprovide shock and/or vibration damping as stated in U.S. Pat. No.5,766,720, which issued on June 16, 1998 to Yamagishi, et al. Thesematerials include natural rubbers and synthetic resins such as polyvinylchlorides, polyurethane, polyamides polystyrenes, copolymerizedpolyvinyl chlorides, and poloyolefine synthetic rubbers as well assynthetic materials such as urethane, EPDM, styrene-butadiene rubbers,nitrites, isoprene, chloroprenes, propylene, and silicones.

The particular type of elastomeric material is not critical but urethanematerial sold under the trademark Sorbothane® is currently employed.Suitable material is also sold by Aero E.A.R. Specialty Composites, asIsoloss VL. The registrant of the mark Sorbothane® for urethane materialis the Hamiltion Kent Manufacturing Company (Registration No.1,208,333), Kent, Ohio 44240.

Generally, the shape and configuration of elastomeric isolators have asignificant effect on the shock and vibration attenuationcharacteristics of the elastomeric isolators. The elastomeric isolatorsemployed in the prior art are commonly formed into geometric 3D shapes,such as spheres, squares, right circular cylinders, cones, rectanglesand the like as illustrated in U.S. Pat. No. 5,776,720. Theseelastomeric isolators are typically attached to a housing to protectequipment within the housing from the effects of shock and vibration.

The prior art elastomeric isolators are generally positioned to rely onan axial compression of the elastomeric material or on tension or shearof the elastomeric material. Generally, if the elastomeric isolator isloaded in the axial compressive mode, where the force between thespaced-apart flat plate is normal to the support surfaces at all pointsof the surfaces, the ability of the elastomeric isolator to attenuateshock and vibration is limited by the compressive characteristics of thematerial. On the other hand, in the axial compressive mode theelastomeric isolators can be used to provide static support to ahousing, which allows a single elastomeric isolator to be placed beneaththe housing to support the static weight of the housing.

In general, if the elastomeric isolators are positioned in a shear ortension mode as opposed to an axial compression mode the elastomericisolators provide better shock and vibration attenuating characteristicsin response to dynamic forces due to shock and vibration. Unfortunately,elastomeric isolators, which operate in a shear or tension mode or inthe axial compression mode, generally can not be placed beneath ahousing to provide static support to the housing without substantiallyeffecting the shock and vibration attenuation characteristics of theelastomeric isolators. Consequently, to provide static support for ahousing, as well as effective shock and vibration attenuationcharacteristics the elastomeric isolators, which operate in the shear ortension mode, may be placed along side or above a housing so that theelastomeric isolators can function in a shear or tension mode whiletensionally supporting the static weight of the housing. The positioningin a shear or tension mode can require placing matching elastomericisolators on each side of the housing. In contrast, the presentinvention provides an elastomeric isolator that provides compressivesupport for a housing with a force component that is normal to twospaced-apart support surfaces only around the peripheral of thesurfaces. The present invention can be placed beneath a housing toprovide static compressive force support for the housing while retainingthe necessary dynamic attenuation characteristics to thereby effectivelyreduce shock and vibration to the housing.

SUMMARY OF THE INVENTION

A shock isolator for simultaneously isolating shocks and supporting astatic load comprising an elastomer material having a set of side wallsand a set of end walls integrally forming a four-sided shock isolatorwith a cavity therein. The multiple-sided shock isolator includes acentral axis, a first elongated support surface and a second elongatedsupport surface with the first elongated support surface and the secondelongated support surface laterally and rotationally positioned withrespect to each other so that any point on the first support surface issupported by the second support surface and vice versa to therebyprovide shock and vibration attenuation and axially offset support. Thatis, there is no solid elastomer compressive axis since there is not aline parallel to a central axis that extends from a point on the firstelongated support surface to a point on the second elongated supportsurface without extending out through the sidewalls i.e. there is nosolid compressive axis.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a multi-sided shock isolator forproviding offset support and shock isolation;

FIG. 2 is a top view of a multi-sided shock isolator for providingoffset support and shock isolation;

FIG. 3 show the position of the first support surface with respect tothe positioning of the second support surface of the four-sided shockisolator of FIG. 1;

FIG. 4 shows a front view of the four-sided shock isolator of FIG. 1;

FIG. 5 shows a side view of the four-sided shock isolator of FIG. 1;

FIG. 6 shows a pair of four-sided shock isolator supporting a housing ona support surface;

FIG. 7 is a partial cross-section view of a side view of a four-sidedshock isolator having a pair of rigid plates secured thereto withdamping material shown;

FIG. 8 is a partial cross-section view of an end view of a four-sidedshock isolator having a pair of rigid plates secured thereto withdamping material shown;

FIG. 9 is a side view showing a pair of four-sided shock isolatorsstacked on top of each other, and

FIG. 10 shows a cross-sectional view of a four-sided shock isolatorunder a static and a dynamic force.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a perspective view of a four-sided shock isolator 10 forsimultaneously providing shock and vibration attenuation while providingaxially offset support A four-sided shock isolator comprises a shockisolator 10 formed from an elastomer material having a set of sidewalls11A and a set of end walls 11B integrally connected to form a chamber 11therein. Located at a first end 10A of four-sided shock isolator 10 isan elongated surface comprising a first elongated-shaped support surface12 for engaging a first member such as a housing or a cabinet andlocated at a second end 10B of four-sided shock isolator 10 is anidentical elongated surface comprising a second rectangular-shapedsupport surface 13 for engaging a second member such as a supportsurface. First support surface 12 comprises parallel side surfaces 14and 14A and parallel end surfaces 15 and 15A with side surfaces 14 and14A having a longer length than the end surfaces 15 and 15A. Similarly,second elongated support surface 13 also comprises identical sidesurfaces and end surfaces with side surface 16 having a longer lengththan the length of end surface 17. As shown in FIG. 1, the side surfaces14 and 14A and 16 of the first and second elongated support surfaces 12and 13 are longer than the end surfaces 15 and 17 of the first andsecond elongated support surfaces 12 and 13.

A central axis 42 is shown in FIG. 1 extending through the center ofchamber 11. The first elongated support surface 12 of shock isolator 10is laterally positioned with respect to the second elongated supportsurface 13 so that any point on the first elongated support surface 12is supported by the second elongated support surface 13 and vice versaso as to permit the shock isolator 10 to simultaneously provide shockand vibration attenuation while providing axially offset support. Thelateral positioning of the elongated support surfaces 12 and 13 resultin the sidewalls 11A of the shock isolator 10 positioned in anonparallel relationship with respect to each other and with the endwalls 11B of the shock isolator 10 also being positioned in anonparallel relationship with respect to each other.

FIG. 2 shows a top view of four-sided shock isolator 10 and FIG. 3 showsa top view of four-sided shock isolator 10 with the hidden boundaries ofsupport surface 13 outlined in dashed lines to further illustrate theposition of the first support surface 12 with respect to the positioningof the second support surface 13 of the four-sided shock isolator 10. Asshown, FIGS. 2 and 3 both illustrate the rotational position of thefirst elongated-shaped support surface 12 with respect to the secondelongated-shaped support 13. Although support surfaces 12 and 13 may beat various rotational positions with respect to each other, FIGS. 2 and3 show the preferred embodiment where elongated support surface 12 isrotationally positioned 90° with respect to support surface 13.

FIG. 4 is an end view of four-sided shock isolator 10 showing the sidesurface 14 of the first elongated support surface 12 with respect to endsurface 17 of second elongated support surface 13. FIG. 5 is a side viewof shock isolator 10 showing the end surface 15 of the first elongatedsupport surface 12 and side surface 16 of the second elongated supportsurface 13 of four-sided shock isolator 10. As shown in FIGS. 4 and 5,the lateral positioning of the first elongated support surface 12 withrespect to the second elongated support surface 13 results in thesidewalls 11A and end walls 11B of shock isolator 10 extending from thefirst support surface 12 to the second support surface 13 at an angle tothereby provide support to sidewalls 11A and end walls 11B. Toillustrate the offset support an axis 42 a is shown extending fromsurface 12 past end surface 17 with the axis spaced a distance “x” fromend surface 17.

FIG. 6 shows a pair of four-sided shock isolator 10 supporting thestatic weight of a housing 16, which may contain equipment to beprotected from shock and vibration, on a support surface 19. Althoughtwo four-sided shock isolators 10 are shown supporting housing 18 whilesimultaneously providing the proper shock and vibration attenuationcharacteristics, a single four-sided shock isolator 10 or more than twofour-sided shock isolator 10 can also provide support for housing 18while at the same time providing the proper shock and vibrationattenuation characteristics.

FIG. 7 is a side view of a four-sided shock isolator 20 and FIG. 8 is anend view of four-sided shock isolator 20 with both FIGS. 7 and 8 showingfour-sided shock isolator 20 having a first rigid plate 23 secured to afirst support surface 21 of shock isolator 20 for engaging a member suchas a housing that is to be isolated from shock and vibration and asecond rigid plate 24 secured to a second support surface 22 of shockisolator 20 for engaging a second member such as a support surface.First rigid plate 23 has parallel sides 23A and 23B and parallel ends23C and 23D. Second rigid plate 24 has parallel sides 24A and 24B andparallel ends 24C and 24D. As shown in the embodiment of FIGS. 7 and 8,sides 23A and 23B of the first rigid plate and sides 24A and 24B of thesecond rigid plate 24 all have longer lengths than the lengths of theends 23C and 23D of the first rigid plate 23 and the ends 24C and 24D ofsecond rigid plate 24.

FIG. 9 shows a pair of four-sided shock isolators 28 and 29, which aresimilar to the shock isolator 20 of FIGS. 7 and 8, stacked in anend-to-end relationship with a rigid plate 30 of shock isolator 28engaging a rigid plate 31 of the shock isolator 29. The stacking offour-sided shock isolators 28 and 29 provide additional axial offsetcompressive support while at the same time providing necessary shock andvibration attenuation characteristics. While the four-sided shockisolators are shown stacked with rigid plates, the plates 30 and 31 neednot be used as the elastomer end surface of the four-sided shockisolator 28 could be secured to the elastomer end surface of four-sidedshock isolator 29.

Referring back to FIGS. 7 and 8, FIGS. 7 and 8 also shows partialcross-sectional views of four-sided shock isolator 20. As shown in FIGS.7 and 8, the rotational positioning of the support surfaces 21 and 22with respect to each other results in the end walls 26 and 26A andsidewalls 27 and 27A of shock isolator 20 secured to the first rigidplate 23 and the second rigid plate 24 being aligned at an angle.

FIG. 7 shows the angling engagement of end wall 26 to rigid plates 23and 24 with end wall 26 engaging the first rigid plate 23 exterior to aninner peripheral boundary 32 located proximate side 23A of first rigidplate 23 and engaging the second rigid plate 24 at position 32A.Position 32, which defines an inner peripheral boundary of rigid plate23 running along side 23A of rigid plate 23 and position 32A, whichdefines inner peripheral boundary of rigid plate 24 and extending alongend 24C. The lateral distance between position 32 and position 32A has adistance “x₁” where distance “x₁” is greater than the thickness of endwall 26 thereby ensuring that there is no axial compressive axisperpendicular to plates 23 and 24 for wall 26.

FIG. 7 also shows the angling engagement of end wall 26A to rigid plates23 and 24 with end wall 26A engaging first rigid plate 23 exterior to aninner peripheral boundary 32B located proximate side 23B of rigid plate23 and engaging second rigid plate exterior to an inner peripheralboundary 32C located proximate end 24D of rigid plate 24. Position 32B,which defines the inner peripheral boundary of rigid plate 23 extendsalong side 23B of rigid plate 23 and position 32C, which defines theinner peripheral boundary of rigid plate 24 extends along end 24D. Thelateral distance between position 32B and position 32C has a distance“x₁” where distance “X₁” is greater than the thickness of the end wall26A thereby ensuring that there is no axial compressive axisperpendicular to plates 23 and 24 for wall 26A.

Referring to FIG. 8, the angling engagement of sidewall 27 to rigidplates 23 and 24 with sidewall 27 engaging the first rigid plate 23exterior to an inner peripheral boundary 33 located proximate end 23C ofrigid plate 23 and engaging the second rigid plate 24 at position 33A.Position 33, which defines an inner peripheral boundary of rigid plate23, extends along end 23C of rigid plate 23 and position 33A, whichdefines the inner peripheral boundary of rigid plate 24 extends alongside 24B. The lateral distance between position 33 and position 33A alsohas a distance “x₂” where distance “x₂” is greater than the thickness ofsidewall 27 thereby ensuring that there is no axial compressive axisperpendicular to plates 23 and 24 for wall 27.

FIG. 8 also shows the angling engagement of sidewall 27A to rigid plates23 and 24 with sidewall 27A engaging the first rigid plate 23 exteriorto an inner peripheral boundary 33B located proximate end 23D of rigidplate 23 and engaging the second rigid plate 24 exterior to an innerperipheral boundary 33C located proximate side 24A of rigid plate 24.Position 33B, which defines the inner peripheral boundary of rigid plate23 extends along end 23D of rigid plate 23 and position 33C, whichdefines the inner peripheral boundary of rigid plate 24 extends alongside 24A. The lateral distance between position 32B and position 32Calso has a distance “x₂” where distance “x₂” is greater than sidewall27A thereby ensuring that there is no axial compressive axisperpendicular to plates 23 and 24 for wall 27A.

The angling of the walls of four-sided shock isolator 20 result in thefirst elongated support surface 21 being laterally positioned withrespect to the second elongated support surface 22 so that any point onthe first elongated support surface 21 is supported by the secondelongated support surface 22 and vice versa so as to permit the shockisolator 20 to simultaneously provide shock and vibration attenuationwhile providing axially offset support. That is the lateral offset ofthe support surfaces 21 and 22 will prevent the end walls 26 and 26A andsidewalls 27 and 27A of shock isolator 20 from acting in a pure axialcompression mode. Instead the end walls 26 and 26A and sidewalls 27 and27A will provide compression support through an axial offset supportthat allows the walls of four-sided shock isolator 20 to movecircumferentially outwards in response to dynamic forces.

Although the first support surface 21 is shown in the present embodimentas being the same size as the second support surface 22, alternativeembodiments may provide for a first support surface having a larger sizethan a second support surface or vice versa.

FIG. 10 shows a cross-sectional view of a four-sided shock isolator 35similar to the shock isolator 20 of FIGS. 7 and 8. To,illustrate theoperation of forces, a first force F₁ acts on a first rigid plate 36 ofshock isolator 35 and a second force F₂ acts on a second rigid plate 37of shock isolator 35. Due to support by the walls of shock isolator 35(only the end walls 38 are shown in FIG. 10), the compressive forcesacting on four-sided shock isolator 35 does not result in pure axialcompression of the walls but instead produces axial offset compressionwhich results in the bulging or outward expansion of the walls asindicated by the dotted lines 39. That is, forces F₁ and F₂ cause thewalls of shock isolator 35 to bulge outward instead of absorbing theforce by direct axial compression of the elastomer.

The positioning of a first support surface 40 and a second supportsurface 41 of four-sided shock isolator 35 at a 90° angle with respectto each other results in support surfaces 40 and 41 of four-sided shockisolator 35 being laterally offset from each other to provide a shockisolator that can support a static load as well as isolate shock andvibration forces from the housing by eliminating a direct axialcompression path through the shock isolator. In addition, the rotatedpositioning of the support surfaces 40 and 41 of four-sided shockisolator 35 will also prevent a significant bias in a single directionthus leading to homogenous shock isolation.

If desired a damping material such as a high-density resilient material34 shown in FIGS. 7 and 8, can be placed in a cavity 20A of the shockisolator 20 to thereby alter the damping characteristics of the shockisolator. For example, a known damping material comprising particles oftungsten carbide or the like can be placed in the cavity.

Referring to FIGS. 7 and 8, the present invention also includes a methodof making a shock isolator for simultaneously providing compressionsupport and shock isolation comprising the steps of: (1) molding anelastomer material into the shape of a four-sided shock isolator 20having sidewalls 27 longer than the width of the end walls 26 with thefirst elongated support surface 21 and the second elongated supportsurface 22 of the shock isolator 20 laterally positioned with respect toeach other so that a line parallel to a central axis of shock isolator20 and extending through first elongated support surface 21 does notextend along an elastomers sidewall through second elongated supportsurface 22 and vice versa to thereby provide shock and vibrationattenuation and axially offset support; (2) attaching first rigidmounting plate 23 to the first elongated support surface 21 andattaching second rigid mounting plate 24 to the second elongated supportsurface 22 of shock isolator 20. The present invention may also includethe step of placing a damping material 34 into the cavity 20A of shockisolator 20.

1. A shock isolator for simultaneously isolating shocks and supporting astatic load comprising: an elastomer material, said elastomer materialhaving a set of connecting walls integrally forming a four-sided shockisolator with a cavity therein, said four-sided shock isolator having acentral axis; and a first elongated support surface located on a firstend of the elastomer material and a second elongated support surfacelocated on an opposing end of the elastomer material with said firstelongated support surface and said second elongated support surfacebeing rotationally positioned with respect to each other so that anypoint on said first support surface is supported by said second supportsurface and vice versa.
 2. The shock isolator of claim 1 wherein thefirst support surface is identical to the second support surface inshape.
 3. The shock isolator of claim 1 wherein the first supportsurface and the second support surface are of different sizes andshapes.
 4. The shock isolator of claim 1 wherein said cavity includes adamping material.
 5. The shock isolator of claim 1 wherein the firstelongated support surface and the second elongated support surface aresubstantially parallel to each other so that a compressive force actingon said first elongated support surface causes the side to bulgepartially outwardly and partially inwardly in response to compressiveforces on either of said first elongated support surface or said secondelongated support surface.
 6. The shock isolator of claim 1 wherein therotational positioning of the first support surface with respect to thesecond support surface is 90° about a longitudinal axis.
 7. A shockisolator for simultaneously isolating shocks and supporting a staticload in an axial offset compression mode comprising: a four-sidedelastomer, said elastomer having a chamber therein; a central axis, saidelastomer having a first end and a second end; a first elongated supportsurface located at the first end of said four-sided elastomers; and asecond elongated support surface located at the second end of saidfour-sided elastomers, said first elongated support surface laterallypositioned with respect to said second elongated support surface so thatany point on said first support surface is supported by said secondsupport surface and vice versa to thereby simultaneously provide shockand vibration attenuation while providing axially offset support withoutallowing a direct compressive path through a longitudinal axis of thematerial.
 8. The shock isolator of claim 7 wherein the first supportsurface is rotationally position at an angle 90° with respect to thesecond support surface.
 9. The shock isolator of claim 7 including afirst rigid mounting plate secured to the first elongated supportsurface of said elastomer and a second rigid mounting plate secured tothe second elongated support surface of said elastomer.
 10. The shockisolator of claim 7 wherein the first elongated support surface is thesame size as the second elongated support surface.
 11. The shockisolator of claim 7 wherein the size of the first elongated supportsurface is different from the size of the second elongated supportsurface.
 12. The shock isolator of claim 7 wherein the four-sidedelastomer consists of four sides none of which are perpendicular to saidfirst elongated support surface.
 13. The shock isolator of claim 7wherein the first elongated support surface and the second elongatedsupport surface are substantially parallel to each other so that acompressive force acting on either the first elongated support surfaceor the second support surface causes the four-sided elastomer to bulgeoutwardly and inwardly in response thereto.
 14. The shock isolator ofclaim 7 including a further four-sided elastomer, said furtherfour-sided elastomer stacked in an end-to-end relationship with saidfour-sided elastomer.
 15. The shock isolator of claim 7 wherein thefirst elongated support surface and the second elongated support surfacecomprises a first rectangular support surface and a second rectangularsupport surface.